BANGKOK (Reuters) -- The United States is concerned about the possible transfer of nuclear technology from North Korea to military-ruled Myanmar, U.S. Secretary of State Hillary Clinton has said.

Clinton's comments, during a visit to Bangkok, came ahead of a regional security meeting in the Thai resort of Phuket, where the most contentious topics will likely be Pyongyang's nuclear programme and how to promote democracy in Myanmar.

"The threat that I have always worried about first and foremost is the proliferation of nuclear weapons and weapons of mass destruction," Clinton said in a television interview in Bangkok to be broadcast later. "So obviously we are very concerned about North Korea and recent reports about perhaps their dealings with what we call Burma."

On July 21, Clinton said she was worried about the possibility of military links between the two countries, both regarded as pariahs in the West.

Talk of Myanmar-North Korea military ties was fueled after a North Korean ship, tracked by the United States in June and July on suspicion of carrying banned arms, appeared headed toward Myanmar before turning around.

Clinton will consult regional players later on July 22 in Phuket about giving North Korea a choice between tighter sanctions if it pursues its nuclear program and wider incentives if it abandons them, U.S. officials said.

She plans separate meetings with the foreign ministers of China, Japan, Russia, and South Korea to plot strategy on how to persuade North Korea to give up its nuclear ambitions.

Those talks precede Asia's biggest annual security gathering, the ASEAN Regional Forum (ARF), which takes place on July 23.

In the last two months North Korea has conducted its second nuclear test, test-fired seven ballistic missiles, and boycotted "six-party" talks on ending its nuclear programs in exchange for economic and diplomatic benefits.Sanctions First

U.S. officials said their main focus was to carry out UN Security Council resolution 1874, which bans all North Korean arms exports, authorizes UN member states to inspect North Korean sea, air, and land cargo and requires them to seize and destroy any goods transported in violation of the sanctions.

However, they said they had discussed a wider package of incentives for the North from the other five parties if Pyongyang were to take credible steps on ending its nuclear program.

"We would like to paint a picture for North Korea of a very stark choice," said one senior official who spoke to reporters on condition that he not be identified.

"If they continue on the current path, it's a path that leads to greater tensions in northeast Asia, more isolation, more steps aimed at...the regime," he added.

The official said the United States hoped to secure greater cooperation from its partners on sanctions if it showed that it was willing to be flexible about providing more incentives.

Seoul had wanted foreign ministers from the other five parties to meet jointly on the sidelines to discuss North Korea.

But Beijing, the closest North Korea has to a major ally and host of the now moribund six-party talks, was against the idea, said a South Korean official with knowledge of the issue.

North Korea has sent a low-level delegation to the talks in Phuket, after sending its foreign minister to previous meetings. There were no announced plans for any of the foreign ministers from the other five parties to meet the North Korean delegation.

The U.S. official declined to detail the new incentives under consideration, saying only that "some of them are familiar, but there are new dimensions associated with this as well."